The Application And Research On Corrosion Prevention Of Substation Grounding Grid Based On Cathodic Protection Principles

Corrosion in grounding grid is coming from the electrochemical corrosion of carbon steel in corrosive soil environment and discharge of grid equipments, which decrease cross-sectional area of grounding grid and even rupture it, causing poor performance ground, threatening the safety of personal and equipment and bringing huge losses.Electrochemical protection technology is a very efficient and economic way to control and reduce metal corrosion. It is based on electrochemical theory of metal corrosion. External corrosion to the ground provideas grounding metal cathode DC current, reduce the metal potential (cathodic polarization), and reduce the tendency of metal corrosion and corrosion rate radically. Achieve the effect of inhibiting corrosion of metallic materials grounding grid.Cathodic protection technology is an electrochemical protection technology. According to the different ways to provide external cathode current, it can be divided into sacrificial anode method and the impressed current method. The method of impressed current cathodic protection relys on the automatic control of constant potential DC power supply to provide a cathodic protection current.The research on grounding grid in substations of Baotou City power company shows that there is serious corrosion in parts of the grounding grid. If left unchecked, it will lead to greater security risks, thereby affecting the power system security and stability operation. In view of this, the method of impressed current cathodic protection is used in grounding grid in Qiaoxi substation of Baotou City power company. It improves the situation of corrosion and provides an effective protection method for other substations.